drivers/usb/ulpi/ulpi-viewport.c

   1 /*
   2  * Copyright (C) 2011 Jana Rapava <fermata7@gmail.com>
   3  * Copyright (C) 2011 CompuLab, Ltd. <www.compulab.co.il>
   4  *
   5  * Authors: Jana Rapava <fermata7@gmail.com>
   6  *          Igor Grinberg <grinberg@compulab.co.il>
   7  *
   8  * Based on:
   9  * linux/drivers/usb/otg/ulpi_viewport.c
  10  *
  11  * Original Copyright follow:
  12  * Copyright (C) 2011 Google, Inc.
  13  *
  14  * SPDX-License-Identifier:     GPL-2.0
  15  */
  16
  17 #include <common.h>
  18 #include <asm/io.h>
  19 #include <usb/ulpi.h>
  20
  21 /* ULPI viewport control bits */
  22 #define ULPI_SS         (1 << 27)
  23 #define ULPI_RWCTRL     (1 << 29)
  24 #define ULPI_RWRUN      (1 << 30)
  25 #define ULPI_WU         (1 << 31)
  26
  27 /*
  28  * Wait for the ULPI request to complete
  29  *
  30  * @ulpi_viewport       - the address of the viewport
  31  * @mask                - expected value to wait for
  32  *
  33  * returns 0 on mask match, ULPI_ERROR on time out.
  34  */
  35 static int ulpi_wait(struct ulpi_viewport *ulpi_vp, u32 mask)
  36 {
  37         int timeout = CONFIG_USB_ULPI_TIMEOUT;
  38
  39         /* Wait for the bits in mask to become zero. */
  40         while (--timeout) {
  41                 if ((readl(ulpi_vp->viewport_addr) & mask) == 0)
  42                         return 0;
  43
  44                 udelay(1);
  45         }
  46
  47         return ULPI_ERROR;
  48 }
  49
  50 /*
  51  * Wake the ULPI PHY up for communication
  52  *
  53  * returns 0 on success.
  54  */
  55 static int ulpi_wakeup(struct ulpi_viewport *ulpi_vp)
  56 {
  57         int err;
  58
  59         if (readl(ulpi_vp->viewport_addr) & ULPI_SS)
  60                 return 0; /* already awake */
  61
  62         writel(ULPI_WU, ulpi_vp->viewport_addr);
  63
  64         err = ulpi_wait(ulpi_vp, ULPI_WU);
  65         if (err)
  66                 printf("ULPI wakeup timed out\n");
  67
  68         return err;
  69 }
  70
  71 /*
  72  * Issue a ULPI read/write request
  73  *
  74  * @value - the ULPI request
  75  */
  76 static int ulpi_request(struct ulpi_viewport *ulpi_vp, u32 value)
  77 {
  78         int err;
  79
  80         err = ulpi_wakeup(ulpi_vp);
  81         if (err)
  82                 return err;
  83
  84         writel(value, ulpi_vp->viewport_addr);
  85
  86         err = ulpi_wait(ulpi_vp, ULPI_RWRUN);
  87         if (err)
  88                 printf("ULPI request timed out\n");
  89
  90         return err;
  91 }
  92
  93 int ulpi_write(struct ulpi_viewport *ulpi_vp, u8 *reg, u32 value)
  94 {
  95         u32 val = ULPI_RWRUN | ULPI_RWCTRL | ((u32)reg << 16) | (value & 0xff);
  96
  97         val |= (ulpi_vp->port_num & 0x7) << 24;
  98         return ulpi_request(ulpi_vp, val);
  99 }
 100
 101 u32 ulpi_read(struct ulpi_viewport *ulpi_vp, u8 *reg)
 102 {
 103         int err;
 104         u32 val = ULPI_RWRUN | ((u32)reg << 16);
 105
 106         val |= (ulpi_vp->port_num & 0x7) << 24;
 107         err = ulpi_request(ulpi_vp, val);
 108         if (err)
 109                 return err;
 110
 111         return (readl(ulpi_vp->viewport_addr) >> 8) & 0xff;
 112 }